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Biomedical subjects

R J Contrada

Publications and source records attributed to R J Contrada.

13 recordsLinked to original sources

T-wave amplitude: on the meaning of a psychophysiological index.

The preceding article by Furedy, Heslegrave and Scher presents a positive evaluation of T-wave amplitude (TWA) as a psychophysiologic index, and rejects the more cautious and less favorable view contained in a paper by Contrada et al. (1989). In this article I propose that the Furedy et al. perspective rests on: (1) a questionable approach to the logic of causal inference; (2) an unsatisfactory view of measurement validity; (3) the use of imprecise and therefore misleading language; (4) a disregard of valuable observations that can be drawn from the data of individual research subjects; (5) an objection to evaluative conclusions that can provide a useful stimulus to empirical inquiry. Close examination of these issues argues for a skeptical view of the state of knowledge regarding the meaning of TWA alterations.

Electrocardiography

Repressive coping and verbal-autonomic response dissociation: the influence of social context.

This study examined whether verbal-autonomic response dissociation in repressive copers is potentiated by conditions that enhance social evaluative concerns. Women classified as repressive, low-anxious, or high-anxious gave a self-disclosing speech in either a private condition (a single researcher observed) or a public condition (3 researchers ostensibly observed). Repressors exhibited heart rate elevations that were greater in magnitude than their self-reports of negative affect, but only in the public condition. High-anxious Ss in both conditions showed an opposite pattern of verbal-autonomic dissociation in which self-reported negative affect exceeded cardiac response. Low-anxious Ss in both conditions showed little responsivity in either channel. Results are interpreted within a self-regulatory framework in which differences in self-concept in the domain of emotionality predispose repressive and high-anxious individuals to engage in contrasting, emotion-focused coping styles.

Adaptation, Psychological

Effects of emotional imagery on physiological and facial responses in Type A and Type B individuals.

Type A behavior was examined in relation to physiologic and facial-expressive changes associated with anger, fear and distress. Affect was induced by an imagery procedure in which subjects recalled and described actual, emotion-related episodes. Type A was assessed by a structured interview. Subjects were healthy men, 21 Type As and 21 Type Bs, whose mean age was 39 yr. Type Bs showed higher systolic blood pressure responses and greater expression of negative affect than Type As. Data analysis also revealed a tendency for enhanced physiologic and facial responses of Type Bs relative to Type As to be greater during fear and distress than during anger. These results appear to reflect a coping process whereby Type A individuals show attenuated facial-expressive and physiologic reactivity as a means of maintaining a sense of control over aversive conditions.

Adult

Effects of isoproterenol on T-wave amplitude and heart rate: a dose-response study.

This report examines the hypothesis that electrocardiographic T-wave amplitude is sensitive to graded increases in beta-sympathetic stimulation of the heart. Beta-adrenergic activity was manipulated pharmacologically in 9 healthy men by bolus infusion of isoproterenol in each of six doses: 0.1, 0.25, 0.5, 1.0, 2.0, and 4.0 micrograms. Results indicated that elevations in heart rate above placebo values increased as a linear function of isoproterenol dose. In contrast, the dose-response curve for T-wave amplitude was best described by a quadratic function: an initial reduction in T-wave amplitude at low levels of isoproterenol infusion was followed by a significant reversal of this effect at higher doses. Comparison of the heart rate and T-wave amplitude data points to limitations in the use of the latter as an index of beta-adrenergic activity. One of several possible explanations for the T-wave results would entail a mechanism that preserves ventricular function at high levels of beta-sympathetic stimulation.

Adult

Alcohol and correspondence between self-report and physiological measures of anxiety.

The present study was designed to determine the main effects of alcohol intoxication on self-report and physiological measures of anxiety. Second, we aimed to assess the role of the Marlowe-Crowne Social Desirability (MCSD) scale in predicting the relationship between self-report and physiological indices of anxiety irrespective of drink content. A final purpose of the study was to determine whether the MCSD could account for discrepancies in the effects of alcohol on the two anxiety response systems. Subjects were male social drinkers who received an 0.70 g/kg dose of alcohol or placebo. Results indicated that irrespective of drink content, subjects with high MCSD scores reported lower levels of anxiety than did subjects with low MCSD scores. This relationship was not evident for heart rate. These results for measures of anxiety were not influenced by drink content.

Adult

Type A behavior, personality hardiness, and cardiovascular responses to stress.

Type A behavior and hardiness were examined as predictors of cardiovascular responses to stress in 68 male undergraduates. Systolic and diastolic blood pressure (SBP and DBP) and heart rate were monitored while subjects performed a difficult mirror-tracing task. Type A assessments based on the Structured Interview, but not those based on the Jenkins Activity Survey, were associated with significantly enhanced SBP and DBP elevations. Hardiness was associated with significantly reduced DBP responsiveness. In addition, a significant interaction indicated that the Type B-high hardiness group showed the least DBP reactivity. A near-significant interaction (p = .06) suggested that Type B-high hardiness subjects also reported the least anger. Further exploration of the data indicated that the challenge component of hardiness accounted for its relationship to DBP reactivity. These results have implications both for the psychophysiologic study of Type A behavior and for understanding the health-promoting effects of hardiness.

Adolescent

Effects of beta-adrenergic activity on T-wave amplitude.

This study addresses the hypothesis that electrocardiographic T-wave amplitude is influenced by beta-adrenergic stimulation of the heart. Beta-adrenergic activity was manipulated both pharmacologically and through behavioral challenge. Under resting conditions, 12 healthy men underwent infusion of placebo and then the beta-agonist, isoproterenol, and the beta-blocker, propranolol, in a counterbalanced, crossover design. During infusion of placebo, subjects also underwent two behavioral challenges, a structured interview and mental arithmetic. Analysis of the resting data indicated that propranolol produced a significant increase in T-wave amplitude, and isoproterenol produced significant T-wave amplitude attenuation. As previously reported, drug effects were also in evidence for heart rate. Behaviorally-induced reduction of T-wave amplitude was observed for mental arithmetic but not structured interview, which again paralleled heart rate data. Both pharmacological and behavioral data reported in this study support the hypothesis that the T-wave is significantly affected by beta-sympathetic influence on the heart. However, a nonspecific effect of heart rate change on T-wave amplitude would also account for these results. The findings are discussed in terms of their implications for the utility of T-wave amplitude in psychophysiological research.

Adult

Task difficulty, cardiovascular response, and the magnitude of goal valence.

Sixty-four young women expected to perform an easy, moderately difficult, or extremely difficult memory task with the opportunity to earn a small incentive for good performance. Cardiovascular (heart rate, systolic and diastolic blood pressure) and subjective measures were taken immediately prior to task performance. Both systolic blood pressure (SBP) responses and ratings of goal attractiveness were nonmonotonically related to expected task difficulty, with the most pronounced SBP elevations and highest goal attractiveness in the moderately difficult task condition. Product-moment correlations among cardiovascular response measures revealed a strong positive association between systolic and diastolic pressure (but not heart rate) change in the easy condition, positive relationships among all measures in the moderately difficult condition, and no significant correlations in the extremely difficult condition. Subjective measures of arousal were not affected by the task difficulty manipulation. Principal findings are discussed in terms of a theoretical model proposed by Brehm (1979) that states that motivation varies as a nonmonotonic function of the difficulty of goal attainment. Intercorrelations among cardiovascular response variables are considered in terms of their possible indication of the mechanisms underlying blood pressure changes associated with variations in motivation.

Adult

Effects of beta-adrenergic stimulation and blockade on cardiovascular reactivity, affect, and type A behavior.

The present study examined the acute effects of drugs that stimulate or block sympathetic nervous system activity on components of Type A behavior, affect, and cardiovascular responses to mental stressors. Either propranolol (a beta-adrenergic blocker), isoproterenol (a beta-agonist), or placebo was infused intravenously at different times in 12 healthy males. In two sessions, placebo (saline) was administered first, followed by a structured interview, challenging mental arithmetic test, and completion of affect scales. The procedure was then repeated with one of the active drugs, presented in counterbalanced order. Results indicated reliable drug effects on both heart rate (HR) and systolic blood pressure (SBP) reactivity to the tasks, with change scores to the tasks markedly increased by isoproterenol. Anxiety and hostility ratings paralleled results for HR and BP, with much of this effect being due to higher affect ratings for isoproterenol. The effect of the drugs on Type A behavior was unexpected, with global Type A and several components lowered by isoproterenol and unaffected by propranolol. These data are discussed in terms of the interfering effects of anxiety on Type A speech components. The influence of isoproterenol on affect and reactivity might reflect the physiologic action of a beta 2-adrenergic positive feedback loop which increases release of endogenous norepinephrine, and/or potentiating effects of emotion on reactivity to stress.

Adult

Comparative effects of two beta-blockers on cardiovascular reactivity and type A behavior in hypertensives.

This study compared the effects of beta-blockers differing in degree of central nervous system penetration on Type A behavior and cardiovascular reactivity to mental stress. Forty-six male hypertensives were assigned randomly to receive either highly lipophilic and nonselective propranolol, hydrophilic and cardioselective atenolol, the diuretic hydrochlorothiazide, or placebo. Subjects were administered parallel forms of the Structured Interview (SI) and performed mental arithmetic and a cognitive task prior to and after 6 weeks of therapy. Results indicated that diuretic and placebo subjects (subsequently combined into a single control group) did not differ and that both beta-blockers reduced heart rate but not blood pressure reactivity to mental stress (p less than 0.02), an effect that was strongest during the mental arithmetic test. Analysis of SI components indicated a reduction only in explosive speech for beta-blockers versus controls (p less than 0.05). For global SI classifications, seven out of 12 subjects (58%) receiving propranolol, three of 12 (25%) receiving atenolol, and four of 22 control subjects (18%) became less Type A (p less than 0.05). These data do not replicate results of a prior study obtained with atenolol and suggest that only a subset of hypertensive individuals show reduced Type A behavior with propranolol. Central nervous system mechanisms may be important in producing these effects.

Adult